The best orchid bark mixes, compared.
Top pick: UK GROW bark and perlite 5 l – Highest score: bark plus perlite, 4.5 from 395 reviews, about £9.99 for 5 litres, for one or two pots. Best value: Miracle-Gro peat-free orchid 10 l – Lowest reliable price per stated litre with its own review set, about £0.60 per litre at about £6 for 10 litres. Updated October 2026.
Orchid bark is graded pine chip used as a free-draining potting medium for epiphytic orchids. On amazon.co.uk you buy it as plain bark or mixed with perlite, and some bags are also described as orchid compost. Most buyers in the UK are replacing a moss plug in a moth orchid. Quality is the chip size you can see. It is not a fertiliser analysis. You judge a suitable bag by the millimetre range, not by the word fine on the title. About 8–15 mm suits moth orchids and cymbidiums. About 5–8 mm suits finer roots. A bag that also says soil or compost can hold more water than plain bark. Perlite adds air and does not feed the plant. One moth orchid needs a small pot. A pot that is too large keeps the chips wet. Use bark-based orchid compost, not multipurpose or loam compost, and replace the chips about every two years before they collapse and stay wet. How to match grade, mix and litres is in the [orchid bark buying guide](/hub/fertiliser-soil-and-bark-mulch/orchid-bark/sub/orchid-bark-buying-guide).
Orchid bark is graded pine chip used as a free-draining potting medium for epiphytic orchids. On amazon.co.uk you buy it as plain bark or mixed with perlite, and some bags are also described as orchid compost.
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Personal buying guide
Question 1 of 2
How many orchids are you potting?
The UK GROW 5 litre orchid bark and perlite mix is listed at £9.99, with 4.5 from 395 amazon.co.uk reviews shared with the 1 litre and 2 litre sizes of the same line. In the 50 UK-tagged reviews read for that parent, buyers say orchids thrive after repotting, and that the mix is light, falls between the roots when the pot is tapped, and does not hold water for long. Chips are described as chunky and clean, and the bag as resealable. No millimetre grade is printed, so you cannot check the title against an 8–15 mm moth-orchid range. Dust appears in the shared review text, and the unit-count field says 1.0 gram, which disagrees with the 5 litre volume, so a price per litre from that field would be wrong. Bullets claim nutrients and a sterilised or pest-free blend, which are listing lines rather than a test result. It is the top pick here when you want bark plus perlite for one or two pots and can rinse dust first.
Pros
Cons
Best for: One or two moth orchids when you want bark plus perlite and will check the chips before you pot.
Less suitable: You need a printed 8–15 mm grade, or you are filling a row of pots from one 5 litre bag.
Specifications
Common questions
Does the listing say this mix includes perlite?
Yes. The title names orchid bark with perlite. The captured pack is 5 litres at £9.99.
Is a peat-free claim printed on this listing?
Not stated. The bullets do claim nutrients, and a sterilised or pest-free blend. Those lines are not a certificate.
What size bag and weight does the capture list?
The volume field says 5 litres and the item weight is 1.2 kg. The unit-count field says 1.0 gram. Those figures disagree and were not corrected.
This 2 litre UK GROW bark-and-perlite pouch is £8.99 and shows 4.5 from 395 reviews, shared with the 1 litre and 5 litre sizes. Reviewers on that parent line describe a light mix that does not hold water for long, chunky pieces, and a resealable bag. One comment on a smaller pack says it felt smaller than expected, though it filled a six-inch pot. Dust is in the shared text, and some buyers had only just repotted, so they could not judge growth. The unit-count field says 1.0 gram, which does not match 2 litres or the 470 g item weight. Bullets claim nutrients and a sterilised blend, and no millimetre grade is printed. At about £4.50 per stated litre it costs more per litre than the 5 litre size of the same mix, so it fits a single small pot.
Pros
Cons
Best for: One moth orchid in a small clear pot when you will not need spare bark for a second plant.
Less suitable: You are repotting several orchids and can use the 5 litre size of the same mix.
Specifications
Common questions
Does the listing say this mix includes perlite?
Yes. The title names orchid bark with perlite. The captured pack is 2 litres at £8.99.
Is a peat-free claim printed on this listing?
Not stated. The bullets claim nutrients and a sterilised blend. No millimetre grade is printed.
What size bag and weight does the capture list?
The volume field says 2 litres and the item weight is 470 g. The unit-count field says 1.0 gram, so it does not agree with the volume and was not corrected.
The 1 litre UK GROW bark-and-perlite pouch is £7.99, again on the shared 4.5 from 395 reviews, with an item weight of 250 g. That sticker is about £8 per stated litre, the expensive end of this capture, and the unit-count field still says 1.0 gram. The same reviews praise drainage and chunky pieces, and they also record dust and packs that felt small. This size’s bullets name nutrients, while the sterilised flag present on the 2 litre and 5 litre rows is absent here. No chip grade is printed. Some buyers in the parent set had only just repotted and could not yet judge recovery. It is a narrow buy for one tiny pot when you have already compared it with the 5 litre bag of the same mix.
Pros
Cons
Best for: A single very small pot when a 2 litre or 5 litre bag would sit unused.
Less suitable: Any repot where the 5 litre size of the same mix is a lower price per litre.
Specifications
Common questions
Does the listing say this mix includes perlite?
Yes. The title names orchid bark with perlite. The captured pack is 1 litre at £7.99.
Is a peat-free claim printed on this listing?
Not stated. The bullets name nutrients. The sterilised line present on the 2 litre and 5 litre sizes is absent here.
What size bag and weight does the capture list?
The volume field says 1 litre and the item weight is 250 g. The unit-count field says 1.0 gram, so it disagrees with the volume and was not corrected.
Miracle-Gro peat-free orchid compost is £6.00 for 10 litres, with 4.5 from 160 reviews on this listing rather than a shared size family. Bullets name large pieces of pine bark, a free-draining structure, and 11 nutrients including nitrogen, phosphorus and potassium. The same bullets say the bag fills six 12 cm pots or one 22 cm pot. Across 39 UK-tagged reviews, buyers mention new growth, a fair price and drainage, and they praise the peat-free name. One reviewer still calls the contents orchid peat, which conflicts with the title and is not a lab result. Several reviews are only a few words and never describe chip size or how long the bark lasts. Perlite is not named, and the country-of-origin field says United Kingdom. It is the best value here on price per stated litre when you want a formulated compost rather than plain graded chips.
Pros
Cons
Best for: Several small orchid pots when you want a low price per litre and a peat-free compost that claims nutrients.
Less suitable: You want inert chips with a printed millimetre grade and you will feed the plant yourself.
Specifications
Common questions
Does the listing say this mix includes perlite?
Perlite is not named. The captured pack is 10 litres at £6.00.
Is a peat-free claim printed on this listing?
Yes. The title says peat free. The bullets also name nutrients, including nitrogen, phosphorus and potassium. That is a listing claim, not a feed schedule.
What size bag and weight does the capture list?
The volume field says 10 litres, the unit count is 10,000 millilitres, and the item weight is 3.62 kg. Those litre figures agree. The country-of-origin field says United Kingdom.
UK GROW Elite is a 10 litre pine-and-perlite bag at £12.99, listed at 4.5 from only nine reviews, with three UK-tagged texts in the file. Bullets say the bark is precision graded, sterilised and pest-free, and the pack is heat-sealed, though no millimetre range is printed. One of those three reviews calls it a little too dusty, with twiggy bits that needed a colander rinse and a sort. After that rinse the same buyer called it good value and still in use months later. Another short review says excellent, and a third says it is good for mixing with other substrates. Nine reviews cannot carry the same weight as the 160-review or 395-review lines in this set. A sterilised claim is not proof the bag arrived insect-free. Inspect the chips before you pot, and treat the star line as a thin sample.
Pros
Cons
Best for: A buyer who will rinse and sort a 10 litre bag and does not need a deep review sample.
Less suitable: You want a bark mix judged by hundreds of amazon.co.uk reviews.
Specifications
Common questions
Does the listing say this mix includes perlite?
Yes. The title names pine bark and perlite. The captured pack is 10 litres at £12.99.
Is a peat-free claim printed on this listing?
Not stated. Bullets say the bark is sterilised and pest-free. That is a listing line, not a certificate, and no millimetre grade is printed.
What size bag and weight does the capture list?
The volume field says 10,000 millilitres, the unit count matches, and the item weight is 2.22 kg. The star line is 4.5 from nine reviews.
The UK GROW 20 litre premium mix is £19.99 and carries 4.4 from 941 reviews, the same parent line as the 5 litre size, so that count is one sample. The title calls it bark, soil or compost, and perlite, while a bullet says peat, soil or very small bark can kill an orchid by holding water. Weight is 5.38 kg and the unit count is 20,000 millilitres, which agrees with the 20 litre volume. In the shared UK reviews, buyers praise a bark-and-perlite balance and decent chips, and some split the delivery so unused mix could be stored. Smell and bugs are mentioned in that same parent set, and smaller sizes in the set are called expensive for the amount. Chip grade in millimetres is not stated, and the peat-free line is a claim on the listing. Choose it when several orchids need a large peat-free bag and you accept the soil-compost wording.
Pros
Cons
Best for: A small collection of orchids when you want one large peat-free bag and will look at the chips before you pot.
Less suitable: A single moth orchid, or you want plain bark with a printed 8–15 mm grade.
Specifications
Common questions
Does the listing say this mix includes perlite?
Yes. The title names bark, soil or compost, and perlite. The captured pack is 20 litres at £19.99.
Is a peat-free claim printed on this listing?
Yes. The listing says peat free. A nutrient analysis is not stated. The title still says soil or compost, while a bullet warns that soil holds too much water.
What size bag and weight does the capture list?
The volume field says 20 litres, the unit count is 20,000 millilitres, and the item weight is 5.38 kg. The litre figures agree. The 941 reviews are shared with the 5 litre size.
The 5 litre UK GROW premium bag is £9.99 with the same 4.4 from 941 reviews as the 20 litre size, so you are not reading a separate test of this pack. Item weight is 750 g against a 5 litre volume, which is a light fill next to the 5.38 kg on the 20 litre row. Buyers in the shared set like the bark-and-perlite balance and say it is ready to use, including as an opener for aroid compost. A recurring complaint is that the price feels high for the amount, and smell or bugs appear in the parent reviews. The listing says peat-free and warns that soil or very fine bark holds too much water, yet the title still says bark soil compost. No chip size in millimetres is given. It suits a small peat-free top-up if the chips look coarse when you open the bag.
Pros
Cons
Best for: A single top-up when you want the peat-free premium mix and the chips look coarse on opening.
Less suitable: You are comparing price per litre with the 20 litre size of the same line, or you want a printed chip grade.
Specifications
Common questions
Does the listing say this mix includes perlite?
Yes. The title names bark, soil or compost, and perlite. The captured pack is 5 litres at £9.99.
Is a peat-free claim printed on this listing?
Yes. The listing says peat free. A nutrient analysis is not stated. The title still uses soil-compost wording.
What size bag and weight does the capture list?
The volume field says 5 litres, the unit count is 5,000 millilitres, and the item weight is 750 g. The litre figures agree. The weight is light next to the 5.38 kg on the 20 litre size of the same line.
The 10 litre UK GROW potting bark is titled 3–15 mm and fine grade, at £12.99, with 4.3 from 96 reviews shared with the bag titled 20 litres. Volume and unit count both say 10 litres, and the item weight is 2.5 kg. Reviewers call the chips good quality and the right size, and some would repurchase, including for bonsai mixes. One reviewer says the material is thin and flaky rather than chunky, so it holds water at the bottom of the pot. Another says many pieces are over the stated 15 mm maximum. Bullets say organic or sustainably sourced without a certification number, and perlite is not named. The word fine on this title is a wide 3–15 mm span, so check the chips if you wanted a tighter medium grade for a moth orchid.
Pros
Cons
Best for: Plain bark for orchids or mixes when you can see the 3–15 mm chips and rinse flakes.
Less suitable: You need perlite already blended, or a bag whose reviews describe consistently chunky 8–15 mm pieces.
Specifications
Common questions
Does the listing say this mix includes perlite?
Perlite is not named. The title is plain potting bark, 10 litres, at £12.99.
Is a peat-free claim printed on this listing?
Not stated. Bullets say organic or sustainably sourced, without a certification number on the captured page.
What size bag and weight does the capture list?
The volume field says 10 litres, the unit count is 10,000 millilitres, and the item weight is 2.5 kg. The litre figures agree. The 96 reviews are shared with the bag titled 20 litres.
This listing is titled 20 litres of 3–15 mm fine potting bark at £16.99, with the same 4.3 from 96 reviews as the 10 litre size. The volume field is empty and the unit count is 10 litres, while the item weight is 7 kg, so a price per litre would be a guess. The shared reviews praise chip quality and a strong bag, and they also include the flake complaint and pieces larger than 15 mm. Bullets claim sustainable organic sourcing without a licence number on the captured page. Perlite is not named. The title’s fine grade covers 3–15 mm, which is wider than the 5–8 mm band specialist shops often call fine. Buy it only after you can see the fill, because the litre fields on the page disagree.
Pros
Cons
Best for: A larger sack of plain 3–15 mm bark when you can check the fill on arrival.
Less suitable: You need a litre figure that matches on the title and in the details before you compare price.
Specifications
Common questions
Does the listing say this mix includes perlite?
Perlite is not named. The title is plain potting bark at £16.99.
Is a peat-free claim printed on this listing?
Not stated. Bullets claim sustainable organic sourcing, without a licence number on the captured page.
What size bag and weight does the capture list?
The title says 20 litres. The volume field is empty, the unit count is 10 litres, and the item weight is 7 kg. Those litre figures disagree, so a price per litre is not scored.
UK GROW’s plain potting bark is titled 8–15 mm and fine grade in a 20 litre pack at £14.99, with 4.0 from 49 reviews. That 8–15 mm span is the range often suggested for moth orchids, but the unit count is 10 litres against the 20 litre title, and the item weight is 5 kg. A reviewer who expected 10 litres measured under 6 litres with a 2 litre jug. Other UK comments call the contents random forest waste, husk and debris, and more than one mentions dust. Some buyers wanted it as mulch or a top dressing rather than orchid compost. The organic wording is a bullet, not a certification. The grade looks right on the title, and the written reviews argue with the bag, so check a fresh sack before you rely on it.
Pros
Cons
Best for: A buyer who wants an 8–15 mm title and will reject the sack if the chips are husk.
Less suitable: You need a consistent orchid grade backed by stronger review comments than debris and short fill.
Specifications
Common questions
Does the listing say this mix includes perlite?
Perlite is not named. The title is plain potting bark at £14.99.
Is a peat-free claim printed on this listing?
Not stated. Organic wording is a bullet, not a certification number.
What size bag and weight does the capture list?
The volume field says 20 litres and the item weight is 5 kg. The unit count is 10 litres, so the litre fields disagree. One reviewer who expected 10 litres measured under 6 litres.
Black Soil Society’s 5 litre orchid mix, sold under Invigortex, is £13.99 with 4.0 from 17 reviews, and seven UK-tagged texts were in the file. The title says chunky pine bark with perlite, hand blended in the UK, for Phalaenopsis. Reviewers dispute that picture: one calls it soil with small bark and perlite, unlike the image, and another says that after filtering dust, muck and tiny perlite little bark remained. One bag arrived with fungus gnats, which is a reason to isolate that sack rather than a claim about every batch. A fill comment guesses about 500 ml against a litre the buyer expected, while the listing volume is 5 litres and the unit count is 1,000 grams beside a 1.7 kg weight, so the numbers do not agree. One buyer says it does the job and matches the advert. At this price and this review depth it stays a cautious buy until you have seen the chips.
Pros
Cons
Best for: Someone who has already opened a bag and found the chunky bark the title describes.
Less suitable: A first moth-orchid repot where you need a larger review sample and a free-draining chip.
Specifications
Common questions
Does the listing say this mix includes perlite?
Yes. The title names chunky orchid bark with perlite. The captured pack is 5 litres at £13.99.
Is a peat-free claim printed on this listing?
Not stated. A nutrient analysis is not stated either. The brand on the listing is Invigortex.
What size bag and weight does the capture list?
The volume field says 5 litres and the item weight is 1.7 kg. The unit count is 1,000 grams. Those figures do not agree and were not corrected.
Eleven amazon.co.uk listings were scored from the stored pages and the UK review notes already on file. Shelf date 20 October 2026. There is no laboratory test. A sterilised, organic or pest-free line without a certificate stays a listing claim. Where the title litres and the unit-count field disagree, price per litre is not scored. A review count shared across pack sizes is one sample. The highest score is the top pick. The best value is the lowest reliable price per stated litre with its own review set. The weights below sum to 100.
Review depth
35%Star rating on amazon.co.uk, then the size of that listing's review file. A parent count shared across pack sizes is one sample, so the larger bag does not earn the count again. Fewer than 20 reviews cannot sit level with a 160-review or 395-review line.
Written reviews
25%Comments that describe drainage, chip size and a usable fill score higher. Flakes, dust, a short fill, smell and insects are deductions. One bag with fungus gnats is that bag, not a claim about every batch.
Fit as orchid bark
20%A stated chip range, perlite named on the listing, peat-free wording, and whether the title also says soil or compost. The word fine is not treated as a grade. A sterilised or organic line without a certificate is not a bonus.
Price per litre
20%Pounds per stated litre only when the volume and the unit-count field agree. A clash, including a unit count of 1.0 gram on a litre pouch, gets no price-per-litre credit.
Match the chip grade and the mix before you match the star line. Plain bark, bark with perlite, and a peat-free orchid compost are not one product. Prices below are amazon.co.uk shelf prices on 20 October 2026. This is not a laboratory test.
Orchid bark is the free-draining medium you use when you repot an epiphytic orchid. UK buyers are usually taking a moth orchid out of a moss plug, or refreshing several plants every couple of years. The Royal Horticultural Society says to use bark-based orchid compost, never multipurpose or loam compost, and to repot about every two years before the chips collapse and stay wet. Chip size and hardness matter more than a fertiliser analysis. Pine bark of this kind carries negligible nutrients.
Specialist shops use about 5–8 mm as fine and about 8–15 mm as medium. Titles here call both 3–15 mm and 8–15 mm fine. Read the millimetres, then look at the chips.
395 reviews cover the 1, 2 and 5 litre bark-and-perlite sizes together. 941 reviews cover the 5 and 20 litre premium mixes together. The larger bag is not a second test.
A dense moss plug stays wet inside bark. A pot that is too big does the same. Remove the plug, use a small pot, and do not water with ice cubes.
Buy the grade you can see. About 8–15 mm is the published range for moth orchids and cymbidiums. About 5–8 mm is the finer band. A title that says fine across 3–15 mm is a wide span, not that finer band. Flakes and pieces over the stated maximum show up in reviews of the plain bark, and they hold more water. Plain bark leaves you to add anything else. Perlite adds air and does not feed.
One moth orchid needs a small pot. A 10 or 20 litre bag is for several plants, replaced about every two years, not a sack you tip into one oversized pot. Overpotting keeps the chips wet. Score the review file by its depth. A shared parent count is one sample. Nine reviews, or seventeen, cannot sit level with 160 or 395. Read the complaints: dust, flakes, a short fill, smell, insects. Then use price per litre only when the volume and the unit-count field agree.
Three typical situations, each with a recommendation from this comparison.
You have one plant, often still in a moss plug, and you need a small bag you can check before you pot. UK GROW bark and perlite 5 l is the top pick at about £9.99, with 4.5 from 395 reviews on a shared parent line. Perlite is named. No millimetre grade is printed, so look at the chips and rinse dust. The unit-count field says 1.0 gram.
You are repotting more than one plant and you will replace the bark about every two years. Miracle-Gro peat-free orchid 10 l is about £6, about £0.60 per litre, with 4.5 from 160 reviews on this listing. Volume and unit count agree. It claims large pine-bark pieces and nutrients. It is a compost, not inert graded chips.
You want a peat-free claim, and you do not need to be told that selling peat is already illegal. UK GROW premium mix 20 l states peat free, names perlite, and is about £19.99 for 20 litres, with 4.4 from 941 reviews shared with the 5 litre size. The title also says soil or compost. Look at the chips before you pot. No millimetre grade is printed.
The top pick for one or two pots is UK GROW bark and perlite 5 l at about £9.99. The listing names bark and perlite, amazon.co.uk shows 4.5 from 395 reviews on a shared parent line, and reviewers say the mix drains and settles between the roots. No millimetre grade is printed, and the unit-count field says 1.0 gram, so a price per litre is not taken from that field. The best value is Miracle-Gro peat-free orchid 10 l at about £6, about £0.60 per litre, with volume and unit count in agreement and 4.5 from 160 reviews on this listing. It is a formulated compost with a nutrient claim, not plain graded chips. The 20 litre premium mix shares 4.4 from 941 reviews with the 5 litre size of that line. Plain 3–15 mm bark at 10 litres has matching litre fields. The bag titled 20 litres of 3–15 mm bark does not. None of these scores is a laboratory test.
UK GROW bark and perlite 5 l
Highest score: bark plus perlite, 4.5 from 395 reviews, about £9.99 for 5 litres, for one or two pots.
Miracle-Gro peat-free orchid 10 l
Lowest reliable price per stated litre with its own review set, about £0.60 per litre at about £6 for 10 litres.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the eleven amazon.co.uk listings captured on 20 October 2026. A peat-free, sterilised or organic line is a listing claim unless a certificate number is printed. No laboratory test was run.
Expert source (DIY & tools): Lee Burkhill (Garden Ninja) (external profile) – public expert commentary used as a research source, not as a contributor to our pages.
This page contains affiliate links to amazon.co.uk (tag pcuk26-21). If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are from the listings. This is not a laboratory test.
